The D1861C direct-modulated laser (DML) module is a cost-effective solution for 10 Gbits/s digital trans-mission up to 50 km using traditional intracity

SMF-28

single-mode fiber links. The 1310 nm wave-

length eliminates the need for concern about disper-sion control over most installed intracity fiber plants. The package contains a high-speed DFB laser chip, thermoelectric cooler, thermistor, optical isolator, and a rear-facet monitor photodiode, which allows for external optical power control.

Figure 1. D1861C DML Electrical Schematic

Pin Information

1. Laser anode is case ground mAp-p drive current.2. A positive current into this pin cools the laser.

SMF-28

is a trademark of Corning Incorporated.

Table 1. Pin Descriptions

Pin No.

Description

1

Thermistor

2

Thermistor

3

Laser Cathode (­), dc Bias

1

4

MPD Anode, (Negative Bias MPD)

5

MPD Cathode

6

Thermoelectric Cooler (+)

2

7

Thermoelectric Cooler (­)

ESD

PROTECTION

TEC

7

6

5

4

3

2

1

­

­

­

+

+

RF

R

MATCH

45

R

TH

10 k

@ 25 °C

ISOLATOR

RF CONNECTOR

MPD

DFB

CHOKE

1-1157(F)

2

Agere Systems Inc.

Preliminary Data Sheet

D1861C 10 Gbits/s 1310 nm DML Module (6 dBm)

March 2001

Absolute Maximum Ratings

Stresses in excess of the absolute maximum ratings can cause permanent damage to the device. These are abso-lute stress ratings only. Functional operation of the device is not implied at these or any other conditions in excess of those given in the operational sections of the data sheet. Exposure to absolute maximum ratings for extended periods can adversely affect device reliability. RF input shall be ac coupled. It is recommended that a series induc-tor of 100